Integrated broadband ceramic capacitor array

Abstract

A monolithic capacitor structure includes opposed and overlapping plates within a dielectric body, which are arranged to form a lower frequency, higher value capacitor. Other conductive structure is located either inside the dielectric body or on an external surface thereof and is effective to form a higher frequency, lower value capacitor in parallel with the lower frequency, higher value capacitor. The resulting array of combined series and parallel capacitors integral with the dielectric body provides effective wideband performance in an integrated, cost-effective structure.

1. A method for mounting a capacitor comprising the steps:
 placing an integrated circuit on a major surface of a printed circuit board; 
 providing a capacitor comprising
 a substantially monolithic dielectric body having a first external surface positioned on and substantially parallel to the major surface of the printed circuit board; 
 a lower frequency, higher value, first capacitor formed by a first plurality of conductive plates in the dielectric body; and 
 a higher frequency, lower value, second capacitor formed by a second plurality of conductive plates in the dielectric body; 
 
 placing the capacitor on the printed circuit board such that the plates of the higher frequency, lower value, second capacitor are closer to the integrated circuit than the plates of the lower frequency, higher value, first capacitor. 
 
     
     
       2. The method of  claim 1  wherein the first plurality of conductive plates comprise respective major surfaces oriented substantially perpendicular to the first external surface and form a plurality of capacitors connected in parallel with each other. 
     
     
       3. The method of  claim 2  wherein the second plurality of conductive plates comprise respective major surfaces oriented substantially perpendicular to the first external surface. 
     
     
       4. The method of  claim 3  wherein the first capacitor is electrically connected in parallel with the second capacitor. 
     
     
       5. An apparatus comprising:
 a printed circuit board; 
 an integrated circuit placed on a major surface of the printed circuit board; 
 a capacitor comprising
 a substantially monolithic dielectric body comprising a first external surface positioned on and substantially parallel to the major surface of the printed circuit board; 
 a lower frequency, higher value, first capacitor formed by a first plurality of conductive plates in the dielectric body; 
 and a higher frequency, lower value, second capacitor formed by a second plurality of conductive plates in the dielectric body, wherein the capacitor is placed on the printed circuit board such that the plates of the higher frequency, lower value, second capacitor are closer to the integrated circuit than the plates of the lower frequency, higher value, first capacitor. 
 
 
     
     
       6. The apparatus of  claim 5  wherein the first plurality of conductive plates comprise respective major surfaces oriented substantially perpendicular to the first external surface and form a plurality of capacitors connected in parallel with each other. 
     
     
       7. The apparatus of  claim 6  wherein the second plurality of conductive plates comprises respective major surfaces oriented substantially perpendicular to the first external surface. 
     
     
       8. The apparatus of  claim 7  wherein the first capacitor is electrically connected in parallel with the second capacitor. 
     
     
       9. A capacitor comprising:
 a substantially monolithic dielectric body comprising one end, an opposite end, and first and second external surfaces; 
 first and second contacts on the first and second external surfaces, respectively; 
 a higher frequency, lower value, first capacitor formed by first conductive plates in the dielectric body near the one end, the first capacitor being electrically connected between the first and second contacts; 
 a higher frequency, lower value, second capacitor formed by second conductive plates in the dielectric body near the opposite end, the second capacitor being electrically connected between the first and second contacts in a parallel circuit with the first capacitor; 
 a lower frequency, higher value third capacitor formed by third conductive plates in the dielectric body intermediate the one end and the opposite end and between the first capacitor and the second capacitor, the third capacitor being electrically connected between the first and second contacts in a parallel circuit with the first capacitor and the second capacitor. 
 
     
     
       10. The capacitor of  claim 9  wherein the first, second and third plates are substantially perpendicular to the first external surface of the dielectric body. 
     
     
       11. The capacitor of  claim 10  wherein the first external surface is substantially parallel to the second parallel surface. 
     
     
       12. A capacitor comprising:
 a substantially monolithic dielectric body having a first external surface; 
 at least one conductive first plate in the dielectric body substantially perpendicular to the first external surface; 
 at least one conductive second plate in the dielectric body substantially perpendicular to the first external surface and forming a first capacitor with the first plate; 
 a conductive first external contact electrically connected to the first plate; 
 a conductive second external contact electrically connected to the second plate; 
 a conductive third plate located in the dielectric body near one end of the dielectric body, the third plate electrically connected to one of the first contact and the second contact and forming a fringe capacitance with an other of the first contact and the second contact. 
 
     
     
       13. The capacitor of  claim 12  further comprising:
 a conductive fourth plate located in the dielectric body near an opposite end of the dielectric body, the first plate and the second plate being located intermediate the one end and the opposite end of the dielectric body and between the third plate and the fourth plate, the fourth plate electrically connected to the one of the first contact and the second contact and forming a fringe capacitance with the other of the first contact and the second contact. 
 
     
     
       14. The capacitor of  claim 12  further comprising:
 a resistive element positioned between the dielectric body and the one of the first contact and the second contact, the resistive element being electrically connected between the one of the first contact and the second contact and the third plate, and the third plate being conductively connected to the one of the first contact and the second contact through the resistive element. 
 
     
     
       15. The capacitor of  claim 12  wherein the first external surface is adapted to be positioned substantially parallel to a major surface of a circuit board. 
     
     
       16. The capacitor of  claim 12  wherein the first external surface is adapted to be positioned substantially perpendicular to a major surface of a circuit board. 
     
     
       17. A capacitor comprising:
 a substantially monolithic dielectric body having a first external surface; 
 conductive first plates in the dielectric body substantially perpendicular to the first external surface; 
 conductive second plates in the dielectric body substantially perpendicular to the first external surface and forming first capacitors with the first plates; 
 a conductive external first contact electrically connected to the first plates; 
 a conductive external second contact electrically connected to the second plates; and 
 conductive third plates located in the dielectric body near one end of the dielectric body, the third plates electrically connected to one of the contacts and forming first fringe capacitances with an other contact near the one end of the dielectric body. 
 
     
     
       18. The capacitor of  claim 17  further comprising:
 conductive fourth plates located in the dielectric body near an opposite end of the dielectric body, the fourth plates electrically connected to the other of the first contact and the second contact and forming fringe capacitances with the one of the first contact and the second contact near the opposite end of the dielectric body, the first capacitors being located intermediate the ends of the dielectric body between the first and the second fringe capacitances. 
 
     
     
       19. The capacitor of  claim 17  further comprising:
 a resistive element positioned between the dielectric body and the one of the first contact and the second contact, the resistive element being electrically connected between the one of the first contact and the second contact and the third plates, and the third plates being conductively connected to the one of the first contact and the second contact through the resistive element. 
 
     
     
       20. A capacitor comprising:
 a substantially monolithic dielectric body having conductive first and second contacts on respective first and second external surfaces of the dielectric body; 
 a lower frequency, higher value first capacitor formed by conductive first and second plates in the dielectric body electrically connected to the first and second contacts, respectively; 
 a higher frequency, lower value second capacitor formed by further conductive plates in the dielectric body; 
 a resistive element electrically connected between one of the first capacitor and the second capacitor and the first contact; and 
 conductive third plates in the dielectric body electrically connected to one of the first contact and the second contact and forming respective fringe effect capacitances with an other of the first contact and the second contact, the fringe effect capacitances being electrically connected in a parallel circuit. 
 
     
     
       21. The capacitor of  claim 20  wherein the first surface is adapted to be positioned substantially parallel to a major surface of a circuit board. 
     
     
       22. The capacitor of  claim 20  wherein the first, second and further plates comprise respective major surfaces substantially perpendicular to the first external surface. 
     
     
       23. The capacitor of  claim 20  wherein the further plates comprise:
 a conductive third plate in the dielectric body; 
 a conductive fourth plate in the dielectric body; and 
 a conductive fifth plate in the dielectric body not electrically connected to either the first contact or the second contact, the fifth plate being substantially parallel to the third plate and the fourth plate and forming respective third and fourth capacitors therewith, the third and fourth capacitors being in a series circuit. 
 
     
     
       24. The capacitor of  claim 23  wherein the resistive element is electrically connected between the series circuit and one of the first contact and the second contact to form a resistance electrically connected in series with the series circuit of the third and fourth capacitors. 
     
     
       25. The capacitor of  claim 23  wherein the third plate is electrically connected to the first plate and the fourth plate is electrically connected to the second plate to place the series circuit and the first capacitor in a parallel circuit, and the resistive element is connected between the parallel circuit and one of the first and second contacts to form a resistance electrically connected in series with the parallel circuit. 
     
     
       26. The capacitor of  claim 23  wherein the third plate forms a first fringe effect capacitor with the fourth plate. 
     
     
       27. The capacitor of  claim 20  wherein the resistive element is electrically connected between the parallel circuit of fringe effect capacitances and one of the first contact and the second contact to form a resistance electrically connected in series with the parallel circuit of fringe effect capacitances. 
     
     
       28. The capacitor of  claim 20  wherein the first capacitor is electrically connected in parallel with the parallel circuit of fringe effect capacitances to form a second parallel circuit, and the resistive element is connected between the second parallel circuit and one of the first and second contacts to form a resistance electrically connected in series with the second parallel circuit. 
     
     
       29. A monolithic capacitor, comprising
 a three-dimensional dielectric body; 
 first and second external conductive contacts disposed on the dielectric body; 
 a first conductive plate internal to the dielectric body, extending within the body and conductively connected to the first external conductive contact; 
 a second conductive plate internal to the dielectric body, extending within the body and conductively connected to the second external conductive contact, the first and second conductive plates being substantially parallel and opposed in at least one region of the body and forming a capacitor therebetween; 
 a third conductive plate internal to the dielectric body, extending within the body and conductively connected to the first external conductive contact, the second and third conductive plates being substantially parallel and opposed in at least one region of the body and forming a capacitor therebetween; 
 a fourth conductive plate disposed within the dielectric body and conductively connected to the first external conductive contact, the fourth conductive plate substantially parallel to and opposed to the third conductive plate to form a capacitor therebetween; 
 a first external conductive plate positioned on an external surface of the dielectric body and conductively connected to the first external conductive contact; 
 at least one first via filled with conductive material disposed in the dielectric body and extending between the first external conductive plate and the fourth conductive plate; 
 a fifth conductive plate disposed within the dielectric body and conductively connected to the second external conductive contact, the fifth conductive plate substantially parallel to and opposed to the third conductive plate; 
 a second external conductive plate positioned on an external surface of the dielectric body and conductively connected to the second external conductive contact, the second external conductive plate being substantially coplanar with the first external conductive plate; and 
 at least one second via filled with conductive material disposed in the dielectric body and extending between the second external conductive plate and the fifth conductive plate. 
 
     
     
       30. The monolithic capacitor of  claim 29  further comprising additional conductive plates internal to the dielectric body, extending within the body and conductively connected to the conductive contacts on respective first and second exterior surfaces thereof, wherein the additional plates are substantially parallel and arranged in opposed pairs in at least one region of the body, the respective plates in each pair extending from respective ones of the contacts, to form additional capacitors. 
     
     
       31. The monolithic capacitor of  claim 29  wherein the third conductive plate is substantially coextensive with the first and second conductive plates. 
     
     
       32. A monolithic capacitor comprising
 a three-dimensional dielectric body, having first and second external conductive contacts; 
 a first conductive plate internal to said dielectric body, extending within said body and conductively connected to said first external conductive contact; 
 a second conductive plate internal to said dielectric body, extending within said body and conductively connected to said second external conductive contact, wherein said first and second conductive plates are substantially parallel and opposed in at least one region of said body, to form a capacitor therebetween; 
 a third conductive plate internal to said dielectric body, extending within said body and not conductively connected to any external conductive contacts, wherein said second and third conductive plates are substantially parallel and opposed in at least one region of said body, to form a capacitor therebetween; 
 a first external conductive plate positioned on an external surface of the dielectric body and conductively connected to the first external conductive contact; and 
 a second external conductive plate positioned on an external surface of the dielectric body and conductively connected to the second external conductive contact, the second external conductive plate being substantially coplanar with the first external conductive plate. 
 
     
     
       33. The monolithic capacitor of  claim 32  further comprising additional conductive plates internal to the dielectric body, extending within the body and conductively connected to the conductive contacts on respective first and second exterior surfaces thereof, wherein the additional plates are substantially parallel and arranged in opposed pairs in at least one region of the body, the respective plates in each pair extending from respective ones of the contacts, to form additional capacitors. 
     
     
       34. The monolithic capacitor of  claim 32  wherein the third conductive plate is substantially coextensive with the first and second conductive plates.